Speaking at the daily coronavirus briefing, the Foreign Secretary added that the Government would continue to monitor the situation “very closely”.
The UK has had strict restrictions on movement since March 23, like many other countries around the world.
Boris Johnson eased some restrictions last week, including asking Brits to go back to work if they cannot work from home, and allowing people to be outside as long as they want, in groups smaller than two.
But many other countries have lifted more restrictions, with Germany allowing top-flight football to restart last weekend and several other countries opening up outdoor spaces in restaurants.
The UK has had more coronavirus-linked deaths than any other European country, while the UK-wide Covid-19 infection rate rose again last week, Government advisors said.
And while the Government has exceeded its target for hiring contact tracers to map the spread of the virus, Mr Raab could not confirm when the contact tracing app – which was supposed to be ready by mid-May – would be rolled out.
But the UK is also suffering economic damage from the coronavirus lockdown. The Treasury has warned that Goverment debt could hit £337 billion for the year, the Telegraph reported last week.
Mr Raab said: “It is true to say that making any changes inherently comes with some risk of spreading the virus compared with simply staying at home.
“But it is also true that staying in permanent lockdown is itself not sustainable on health grounds or economic grounds.
“That is why we have only eased measures where it can be done with the lowest risk possible.
“That’s also why we are watching the impact of every change we make very closely.”
His comments come as the deputy chief medical officer defended only adding anosmia – losing a sense of taste and smell – to the list of official Covid-19 symptoms on Monday.
Other countries including France added anosmia to their symptoms list weeks earlier, and Britain may have missed more than 100,000 coronavirus cases by leaving it out until Monday, a scientist at King’s College London has claimed.
Professor Tim Spector told the BBC’s Today Programme: “At the moment, people are being told to go back to work if they’re a care worker, and they’ve got something like loss of smell or taste or severe muscle pains or fatigue – things that we know and we’ve shown are related to being swabbed positive.
“This country is missing the ball in underestimated cases but also putting people at risk, and continuing the epidemic.”
But Jonathan Van-Tam said that UK health authorities had undertaken “painstaking” work to make sure that it was appropriate to include anosmia on the symptoms list and that it wouldn’t contribute significantly to any missed cases.
The deputy chief medical officer told the daily coronavirus briefing: “The point about anosmia is it doesn’t always come as the first symptom.
“Even if it does, it is followed by the cough, the fever and many of the other symptoms I have talked about…
“So you don’t miss those cases.
“The important thing was to work out if this would add any sensitivity to the diagnostic cluster we were using and the answer is that it makes a small – a very small – difference and we have therefore decided to do it.”